Study Of The Energy-efficient Routing Algorithm Of Underground ZigBee Wireless Network

When the accidents occur in the underground coal mine, it requires the communication system being able to transmit the different data collected by the sensors in time. Unfortunately, if the Zigbee nodes run out of energy, the communication between the underground and above ground will be broken off and will result in a big trouble in the following rescue. In this thesis, we study the Zigbee technology and analyze the effect of the environment factors which will affect the application of Zigbee in the underground. Moreover, a novel energy efficient Zigbee routing algorithm is proposed to figure out a solution to the high efficiency issues in the underground communication system.Firstly, the Zigbee technology is introduced. On this basis, the hierarchical tree routing algorithm and the data transmission process of the AODVjr algorithm are analyzed. Furthermore, the complex and changeable environment where the Zigbee nodes work is analyzed. The characteristics of the node is interfered reflected in network topology,energy supply and wireless transmission, which causes the restriction of the Zigbee routing algorithm in the underground coal mine.Secondly, according to the specific underground characteristics, a novel hierarchical tree routing algorithm which is based on the neighbor table is proposed in this thesis. Moreover, a new method for flag setting in the routing discovery process and for setting the RREQ broadcast range in the AODVjr routing algorithm is studied. Meanwhile, an dynamic residual energy threshold is set for the Zigbee nodes to find the energy efficient ZigBee routing algorithm which is suitable for the underground environment.Finally, The simulation results show that the proposed energy efficient Zigbee routing algorithm has a better perform in terms of average end-to-end time delay, node survival rate, packet delivery rate and network residual energy in the given underground tunnel environment.